1. Field of the Invention
The present invention relates to a field emission display (FED) process, and more particularly, to a method of bonding spacers to an anode plate of the FED.
2. Description of the Related Art
Recently, since field emission display (FED) devices have the advantages of spontaneous high-brightness, lightweight, thin, and power efficient characteristics, FED technology has received increased industry attention. Flat panel displays utilizing FED technology employ a matrix-addressable array of cold, pointed field emission cathodes in combination with a luminescent phosphor screen.
It is known in the art to make spacers for use in field emission displays for the purpose of maintaining the separation between the cathode and the anode plates. Conventionally, an anodic bonding technology is used to bond the spacers to the anode plate.
FIG. 1 is a sectional view illustrating the conventional anodic bonding process of a field emission display. Numeral 100 indicates a heating plate. Numeral 110 indicates a glass plate. A transparent electrode 112 is formed on the glass plate 110. Phosphor regions 114 are separately formed on the transparent electrode 112, wherein a black matrix material 116 is provided to separate the phosphor regions 114 from one another. An aluminum film 118 is formed on the phosphor regions 116 and the black matrix material 116.
In FIG. 1, the whole glass plate 110 is put on the heating plate 100 to attain the bonding temperature of above 300° C. Thus, the spacers 120 connected to a conductive plate 130 can be bonded to the aluminum film 118 above the black matrix material 116 by the anodic bonding method, wherein the conductive plate 130 and the aluminum film 118 are electrically connected to a D.C. power supply.
Nevertheless, because of the higher bonding temperature process (above 300° C.), thermal stress occurs in the glass plate 110, thereby deforming the glass plate 110 and affecting other devices thereon. Also, the entire glass plate 110 requires heating, so the conventional method is relatively power hungry and inefficient. Additionally, coordination of the size of the heating plate 100 and the glass plate 110, cause great inconvenience in field emission display fabrication.